Extreme Weather and Climate Events

American Samoa is vulnerable to sea-level rise in part due to the steep terrain of its islands. This terrain requires the majority of the islands’ villages and infrastructure to be located along thin strips of coastal land. The situation is worsened by the recently recognized rapid sinking of the islands, which was triggered by the 2009 Samoa earthquake and is predicted to last for...

Ecosystems such as coral reefs and mangroves provide an effective first line of defense against coastal hazards and represent a promising nature-based solution to adapt to sea-level rise. In many areas, coral reefs cause waves to break and lose energy, allowing for sediment to accumulate on the inshore portion of reef flats (i.e. the shallowest, flattest part of a reef) and mangroves to...

In the Northern Rockies, the annual area burned by wildfires has risen sharply in recent decades and is expected to continue growing. As a result, burned forests increasingly comprise a significant portion of the land base. However, burned areas represent a difficult paradox for land managers, especially in the context of other climate-linked disturbances (e.g., droughts, bark beetle...

Changing climate in the “Ridge-to-Reef" (R2R) and “Icefield-to-Ocean" (I2O) ecosystems of Hawai‘i and Southeast Alaska is expected to influence freshwater resources, extreme precipitation events, intensity of storms, and drought. Changes in these regions will not be uniform, rather they will depend on elevation and watershed location due to their steep-gradient terrains. A better...

Much of the biodiversity of the southeastern U.S. is found in grasslands, including meadows, prairies, glades, and savannas. These grasslands provide vital habitat to a variety of plants and animals, but many grassland types have undergone over 90% loss due to fire suppression and urban sprawl. The remaining grassland patches—remnants—now face emerging threats from invasive species and...

Prescribed burning is a primary tool used to reduce wildfire risk and manage ecosystems to achieve a range of ecological, economic and societal goals.  The ability of fire managers to use prescribed fire as a management tool is complicated in regions such as the Southeast because of rapid population growth, extensive suburban development, and a changing climate. Such change restricts...

Aspen forests are considered keystone ecosystems, meaning that loss of aspen habitat would result in negative impacts to numerous plant and animal species. Aspen also provide important economic and social benefits, including drawing tourists, serving as potential fire breaks, improving local economies, and providing forage for wildlife and livestock. Ecologically-valuable aspen forests...

The northwestern United States (Oregon, Washington, Idaho, and western Montana) are experiencing increasing air temperatures, declines in snowpack, altered hydrology, and more frequent and severe wildfire, drought, and insect and disease outbreaks as a result of climate change. These factors, alone and in combination with existing non-climate stressors, present a significant challenge to...

Climate change is already affecting ecosystems, and will likely trigger significant and permanent changes in both ecological and human communities. Such transformations are already occurring in the Arctic region of Alaska, where temperatures are warming at twice the global average and causing some ecosystems to transition to new states. Arctic warming has led to coastal erosion that has...

Forests in the western U.S. are increasingly impacted by climate change. Warmer and drier conditions both increase fire activity in western forests and make it more difficult for forests to recover after wildfires. If forests fail to recover, they may shift to non-forest ecosystems like grasslands or shrublands. It is important to understand where fires may result in the loss of forests...

Freshwater mussels are an important component of freshwater ecosystems. They can filter a large amount of water, affecting both water clarity and water chemistry. Their shells provide physical habitat for other organisms, they re-direct necessary nutrients to the bottom of the water column, and their excreted material can enhance the growth of algae and macroinvertebrates. However...

Climate change is likely to impact erosion rates, the magnitude and frequency of extreme rainfall/mass wasting events, and the accumulation of sediment in coastal areas. However, long-term rates of erosion and sediment delivery to coastal systems are poorly constrained and there is limited understanding of the relative effects of climate change versus land-use change on these processes